Spa shell



FIG. 1 is a top front perspective of a spa shell showing my new design, the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a cross-sectional view taken along line 3—3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along line 4—4 of FIG. 2;

FIG. 5 is a cross-sectional view taken along line 5—5 of FIG. 2; and,

FIG. 6 is a cross-sectional view taken along line 6—6 of FIG. 2.

The broken lines shown in the drawings represent unclaimed portions of the design and form no part thereof. 

The ornamental design for a spa shell, as shown and described. 